When a telephone user makes a phone call, the phone device on the receiving end displays the identity of the calling device. In some cases, the calling user has an option to disable the display of the calling user's identification.
At present, there are many traditional and voice over IP (VoIP) service providers that provide phone services to users and it is not unusual for a user for have multiple phone numbers. For example, a user might get a Skype™ phone number, a Google Voice™ phone number, a mobile phone number, a home phone number and so on. However, the user may not want to publish all his/her numbers to the world. Also, a user may be using some phone services only for calling others and may not wish to receive a call back on the same number. For example, a user may use his Skype number for calling others but would like others to always call the user back to the user's home phone number. This way, others need to remember and store just one number for the calling user. Moreover, if the calling user makes a call from a new phone number with the particular phone number configured as calling line identification (CLI), the receiving phone user will know who is calling before picking up the phone. In order not to publish the number from which the user makes calls, the CLI needs to be changed to a desired phone number.